Antimicrobial activity of extracts from exotic fruits and vegetables

Novel sources of antimicrobial agents need to be identified to address the looming crisis of antimicrobial resistance. The overall goal of the described experiments was to determine whether extracts of exotic vegetables, mushrooms, and herbs have antimicrobial properties. Vegetable and herbal extracts were purchased from online supplier. Fresh vegetable roots and mushrooms were run through a commercially available juicer to obtain aqueous extracts. Extracts were spotted onto filter paper disks and activity assessed by measuring the zone of inhibition for both E. coli K-12 and B. subtilis as representative Gram-negative and Gram-positive organisms, respectively. Synergy testing was also performed by placing disks spotted with extracts in close proximity to one another. Amongst commercial extracts, prominent Gram-positive activity was found for Echinacea , grapefruit seed, olive leaf, and golden seal extracts; and prominent mixed Gram-negative and Gram-positive activity was found for clove extract. Amongst fresh vegetable and mushroom juicing extracts, Gram-positive activity was detected for celery root.